I don't have one of those guns to look at, but IIRC, the safety does not block the sear like the M1911. Instead, it is intended to cam the hammer back off the sear and then block it so it won't drop. Those guns are a Spanish design (some are made in Spain), and that is the common design for many Spanish and Spanish type pistols, like the Argentine Ballester-Molina. It is a good system but the safety needs careful fitting to make sure it works the way intended. If that is not done, the pistol can be effectively without a safety and dangerous.
In all the cases mentioned, I recommend taking the gun to a gunsmith, and explain to him how the safety is supposed to work and ask him to fit it so it does so. Note also that with that type of safety, the trigger can be pulled while the hammer is cocked and the safety on without dropping the hammer, unlike the M1911 type. Also the safety must be checked for sear reset by cocking the hammer (gun empty, of course), setting the safety to ON, pulling the trigger, then releasing the safety. If the hammer drops to half cock when the safety is released, the safety is defective or is not fitted properly.
(Edited to add "and the safety on without dropping the hammer" above. With the hammer cammed back and blocked, the trigger and sear are free to move.)
Jim